Synthesis and properties of alternating polyfluorene copolymers with redshifted absorption for use in solar cells

Three fluorene based alternating copolymers with redshifted absorption were synthesized and used as the active layer in photodiodes. The polymers are soluble in common solvents. The photodiodes cover a large part of the solar spectrum with high external quantum efficiency and we reach 2.4% power conversion efficiency for the best device in this study.